The average lifespan of a car battery is approximately 3-5 years. You can use one of two methods to check that: Is your car battery in good condition?: a) Voltmeter: 1. Turn off the engine 2. Remove the battery positive terminal cover. Check and clean the battery terminals. 3. Connect the positive terminal of the voltmeter to the positive terminal of the battery. The positive terminal of the voltmeter is usually red. 4. Connect the negative voltmeter to the negative battery terminal. 5. Check the voltmeter. If your battery is in good condition The voltage should be between 12.4 and 12.7 volts - a reading below 12.4 volts means the battery needs to be charged - if the reading is below 12.2 volts it indicates a "leakage" which Makes charging slower - If the reading exceeds 12.9 volts, it means there is overvoltage. Turn on high beam to remove excess electrical charge on the surface. Overvoltage may be a sign that the alternator is overcharging the battery. B) Crank the engine: 1. Crank the engine by turning the ignition until the starter engages and holding it for 2 seconds. Have someone crank the engine while you. Check for decreased battery voltage. 2. Check the readings from the Power Probe on the crank. Should not be less than 9.6 volts - A battery with a volt reading of less than 9.6 volts means that the battery is sulfated and not holding/accepting a charge.